Motor assembly with heat exchanger for catheter pump

ABSTRACT

A catheter pump is disclosed. The catheter pump can include an impeller and a catheter body having a lumen therethrough. The catheter pump can also include a drive shaft disposed inside the catheter body. A motor assembly can include a chamber. The motor assembly can include a rotor disposed in the at least a portion of the chamber, the rotor mechanically coupled with a proximal portion of the drive shaft such that rotation of the rotor causes the drive shaft to rotate. The motor assembly can also comprise a stator assembly disposed about the rotor. The motor assembly can also include a heat exchanger disposed about the stator assembly, the heat exchanger may be configured to direct heat radially outward away from the stator assembly, the rotor, and the chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/106,675, filed on Jan. 22, 2015, the entire contents of which arehereby incorporated by reference herein in their entirety and for allpurposes.

BACKGROUND OF THE INVENTION Field of the Invention

This application is directed to catheter pumps for mechanicalcirculatory support of a heart.

Description of the Related Art

Heart disease is a major health problem that has high mortality rate.Physicians increasingly use mechanical circulatory support systems fortreating heart failure. The treatment of acute heart failure requires adevice that can provide support to the patient quickly. Physiciansdesire treatment options that can be deployed quickly andminimally-invasively.

Mechanical circulatory support (MCS) systems and ventricular assistdevices (VADs) have gained greater acceptance for the treatment of acuteheart failure, such as to stabilize a patient after cardiogenic shock,during treatment of acute myocardial infarction (MI) or decompensatedheart failure, or to support a patient during high risk percutaneouscoronary intervention (PCI). An example of an MCS system is a rotaryblood pump placed percutaneously, e.g., via a catheter without asurgical cutdown.

In a conventional approach, a blood pump is inserted into the body andconnected to the cardiovascular system, for example, to the leftventricle and the ascending aorta to assist the pumping function of theheart. Other known applications include pumping venous blood from theright ventricle to the pulmonary artery for support of the right side ofthe heart. Typically, acute circulatory support devices are used toreduce the load on the heart muscle for a period of time, to stabilizethe patient prior to heart transplant or for continuing support.

There is a need for improved mechanical circulatory support devices fortreating acute heart failure. There is a need for devices designed toprovide near full heart flow rate and inserted percutaneously (e.g.,through the femoral artery without a cutdown).

There is a need for a pump with improved performance and clinicaloutcomes. There is a need for a pump that can provide elevated flowrates with reduced risk of hemolysis and thrombosis. There is a need fora pump that can be inserted minimally-invasively and provide sufficientflow rates for various indications while reducing the risk of majoradverse events.

In one aspect, there is a need for a heart pump that can be placedminimally-invasively, for example, through a 15FR or 12FR incision. Inone aspect, there is a need for a heart pump that can provide an averageflow rate of 4 Lpm or more during operation, for example, at 62 mmHg ofhead pressure.

While the flow rate of a rotary pump can be increased by rotating theimpeller faster, higher rotational speeds are known to increase the riskof hemolysis, which can lead to adverse outcomes and in some casesdeath. Higher speeds also lead to performance and patient comfortchallenges. Many percutaneous ventricular assist devices (VADs) havedriveshafts between the motor and impeller rotating at high speeds. Somepercutaneous VADs are designed to rotate at speeds of more than 15,000RPM, and in some case more than 25,000 RPM in operation. The vibration,noise, and heat from the motor and driveshaft can cause discomfort tothe patient when positioned, especially when positioned inside the body.Accordingly, there is a need to for a device that improves performanceand patient comfort with a high speed motor.

There is a need for a motor configured to drive an operative device,e.g., a impeller, at a distal portion of the pump. It can be importantfor the motor to be configured to allow for percutaneous insertion ofthe pump's impeller.

These and other problems are overcome by the inventions describedherein.

SUMMARY OF THE INVENTION

There is an urgent need for a pumping device that can be insertedpercutaneously and also provide full cardiac rate flows of the left,right, or both the left and right sides of the heart when called for.

In one embodiment, a catheter pump system is disclosed. The catheterpump system can include an impeller and a catheter body having a lumentherethrough. The catheter pump system can include a drive shaftdisposed inside the catheter body and coupled with the impeller at adistal portion of the drive shaft. The catheter pump system can includea motor assembly comprising a rotor mechanically coupled with a proximalportion of the drive shaft. The catheter pump system can include a heatexchanger coupled with the motor assembly to remove heat therefrom, theheat exchanger comprising a volume to receive fluid.

In another embodiment, a catheter pump system is disclosed. The catheterpump system can include an impeller and a catheter body having a lumentherethrough. The catheter pump system can include a drive shaftdisposed inside the catheter body and coupled with the impeller at adistal portion of the drive shaft, the drive shaft configured such thatrotation of the drive shaft causes the impeller to rotate. The catheterpump system can include a motor assembly. The motor assembly can includea motor housing and a chamber disposed in the motor housing, at least aportion of the chamber in fluid communication with the lumen of thecatheter body. The motor assembly can include a damper configured toreduce the transmission of vibrations from the motor assembly.

In yet another embodiment, a catheter pump system is disclosed. Thecatheter pump system can include an impeller and a catheter body havinga lumen therethrough, the impeller mechanically coupled with a distalportion of the catheter body. The catheter pump system can include aguidewire guide tube disposed through the lumen from a proximal portionof the catheter pump to a distal portion of the catheter pump, theguidewire guide tube configured to receive a guidewire therein. Thecatheter pump system can include an end cap secured to a proximal endportion of the guide tube, the end cap configured such that axialmovement of the end cap relative to the catheter body causes theguidewire guide tube to be removed from the catheter pump. The catheterpump system can include a resealable closure device disposed at aproximal portion of the catheter pump, the closure device configuredsuch that when the guidewire guide tube is removed from the catheterpump, the closure device encloses the proximal portion of the catheterpump.

In another embodiment, a catheter pump system is disclosed. The catheterpump system can include an impeller and a catheter body having a lumentherethrough. The catheter pump system can include a drive shaftdisposed inside the catheter body and coupled with the impeller at adistal portion of the drive shaft. The catheter pump system can includea motor assembly. The motor assembly can comprise a housing and a statorassembly within the housing. The motor assembly can comprise a rotorpositioned within the stator assembly, the rotor commutated by thestator, the rotor connected to a proximal portion of the drive shaft.The motor assembly can comprise a thermal layer disposed within thehousing and configured to transfer heat away from the stator and/or therotor.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the subject matter of this applicationand the various advantages thereof can be realized by reference to thefollowing detailed description, in which reference is made to theaccompanying drawings in which:

FIG. 1A illustrates one embodiment of a catheter pump with an impellerassembly configured for percutaneous application and operation.

FIG. 1B is a schematic view of one embodiment of a catheter pump systemadapted to be used in the manner illustrated in FIG. 1A.

FIG. 1C is a schematic view of another embodiment of a catheter pumpsystem.

FIG. 2A is a side plan view of a motor assembly of the catheter pumpsystem shown in FIG. 1B, according to one embodiment.

FIG. 2B is a side plan view of the motor assembly of the catheter pumpsystem shown in FIG. 1B, according to another embodiment.

FIG. 2C is a side plan view of the motor assembly of the catheter pumpsystem shown in FIG. 1B, according to yet another embodiment.

FIG. 3 is a perspective exploded view of a portion of the motorassemblies shown in FIGS. 2A-2C.

FIG. 3A is a schematic view of a heat exchanger, according to anotherembodiment.

FIG. 4 is a schematic perspective view of the motor assembly withvarious vibration-reducing components.

FIG. 5A is a schematic perspective view of an interface between anoutput shaft of the motor assembly and a drive shaft of the catheterpump.

FIG. 5B is a cross-sectional perspective view, taken through thelongitudinal axis of the catheter, showing more details of the interfaceshown in FIG. 5A.

FIG. 6 is an image of a cap and a female receiver for releasablysecuring a guide tube in a lumen that extends through the motor assemblyof FIG. 4, with the guide tube not shown.

More detailed descriptions of various embodiments of components forheart pumps useful to treat patients experiencing cardiac stress,including acute heart failure, are set forth below.

DETAILED DESCRIPTION

This application is generally directed to apparatuses for inducingmotion of a fluid relative to the apparatus. Exemplars of circulatorysupport systems for treating heart failure, and in particular emergentand/or acute heart failure, are disclosed in U.S. Pat. Nos. 4,625,712;4,686,982; 4,747,406; 4,895,557; 4,944,722; 6,176,848; 6,926,662;7,022,100; 7,393,181; 7,841,976; 8,157,719; 8,489,190; 8,597,170;8,721,517 and U.S. Pub. Nos. 2012/0178986 and 2014/0010686, the entirecontents of which patents and publications are incorporated by referencefor all purposes. In addition, this application incorporates byreference in its entirety and for all purposes the subject matterdisclosed in each of the following concurrently filed applications andthe provisional applications to which they claim priority: ApplicationNo. ______, which corresponds to attorney docket no. THOR.127A, entitled“REDUCED ROTATIONAL MASS MOTOR ASSEMBLY FOR CATHETER PUMP,” filed on thesame date as this application and claiming priority to U.S. ProvisionalPatent Application No. 62/106,670; and Application No. ______, whichcorresponds to attorney docket no. THOR.130A, entitled “ATTACHMENTMECHANISMS FOR MOTOR OF CATHETER PUMP,” filed on the same date as thisapplication and claiming priority to U.S. Provisional Patent ApplicationNo. 62/106,673.

In one example, an impeller can be coupled at a distal portion of theapparatus. Some embodiments generally relate to various configurationsfor a motor assembly adapted to drive an impeller at a distal end of acatheter pump, e.g., a percutaneous heart pump. In such applications,the disclosed motor assembly is disposed outside the patient in someembodiments. In other embodiments, the disclosed motor assembly and/orfeatures of the motor are miniaturized and sized to be inserted withinthe body, e.g., within the vasculature.

FIGS. 1A-1B show aspects of an exemplary catheter pump 100A that canprovide high performance, e.g., high blood flow rates. As shown in FIG.1B, the pump 100A includes a motor assembly 1 driven by a console 122,which can include an electronic controller and various fluid handlingsystems. The console 122 directs the operation of the motor 1 and aninfusion system that supplies a flow of fluid (e.g., saline) in the pump100A. Additional details regarding the console 122 may be foundthroughout U.S. Patent Publication No. US 2014/0275725, the contents ofwhich are incorporated by reference herein in their entirety and for allpurposes.

The pump 100A includes a catheter assembly that can be coupled with themotor assembly 1 and can house an impeller in an impeller assembly 116Awithin a distal portion of the catheter assembly of the pump 100A. Invarious embodiments, the impeller is rotated remotely by the motor 1when the pump 100A is operating. For example, the motor 1 can bedisposed outside the patient. In some embodiments, the motor 1 isseparate from the console 122, e.g., to be placed closer to the patient.In the exemplary system the pump is placed in the patient in a sterileenvironment and the console is outside the sterile environment. In oneembodiment, the motor is disposed on the sterile side of the system. Inother embodiments, the motor 1 is part of the console 122.

In still other embodiments, the motor is miniaturized to be insertableinto the patient. For example, FIG. 1C is a schematic view of anotherembodiment of a catheter pump system. FIG. 1C is similar to FIG. 1B,except the motor 1 is miniaturized for insertion into the body. As shownin FIG. 1C, for example, the motor 1 can be disposed proximal theimpeller assembly 116A. The motor 1 can be generally similar to themotor assembly shown in FIGS. 2A-2C, except the motor 1 is sized andshaped to be inserted into the patient's vasculature. One or moreelectrical lines may extend from the motor to the console outside thepatient. The electrical lines can send signals for controlling theoperation of the motor. Such embodiments allow a drive shaft coupledwith the impeller and disposed within the catheter assembly to be muchshorter, e.g., shorter than the distance from the aortic valve to theaortic arch (about 5 cm or less). Some examples of miniaturized motorcatheter pumps and related components and methods are discussed in U.S.Pat. No. 5,964,694; U.S. Pat. No. 6,007,478; U.S. Pat. No. 6,178,922;and U.S. Pat. No. 6,176,848, all of which are hereby incorporated byreference herein in their entirety for all purposes. Various embodimentsof the motor assembly 1 are disclosed herein, including embodimentshaving a rotor disposed within a stator assembly. In variousembodiments, waste fluid can pass through a housing 4 in which the rotoris disposed to help cool the motor assembly 1.

FIG. 1A illustrates one use of the catheter pump 100A. A distal portionof the pump 100A including a catheter assembly including the impellerassembly 116A is placed in the left ventricle LV of the heart to pumpblood from the LV into the aorta. The pump 100A can be used in this wayto treat a wide range of heart failure patient populations including,but not limited to, cardiogenic shock (such as acute myocardialinfarction, acute decompensated heart failure, and postcardiotomy),myocarditis, and others. The pump can also be used for various otherindications including to support a patient during a cardiac inventionsuch as as a high-risk percutaneous coronary intervention (PCI) or VFablation. One convenient manner of placement of the distal portion ofthe pump 100A in the heart is by percutaneous access and delivery usinga modified Seldinger technique or other methods familiar tocardiologists. These approaches enable the pump 100A to be used inemergency medicine, a catheter lab and in other medical settings.Modifications can also enable the pump 100A to support the right side ofthe heart. Example modifications that could be used for right sidesupport include providing delivery features and/or shaping a distalportion that is to be placed through at least one heart valve from thevenous side, such as is discussed in U.S. Pat. No. 6,544,216; U.S. Pat.No. 7,070,555; and US 2012-0203056A1, all of which are herebyincorporated by reference herein in their entirety for all purposes.

The impeller assembly 116A can be expandable and collapsible. In thecollapsed state, the distal end of the catheter pump 100A can beadvanced to the heart, for example, through an artery. In the expandedstate the impeller assembly 116A is able to pump blood at relativelyhigh flow rates. In particular, the expandable cannula and impellerconfiguration allows for decoupling of the insertion size and flow rate,in other words, it allows for higher flow rates than would be possiblethrough a lumen limited to the insertion size with all other thingsbeing equal. In FIGS. 1A and 1B, the impeller assembly 116A isillustrated in the expanded state. The collapsed state can be providedby advancing a distal end 170A of an elongate body 174A distally overthe impeller assembly 116A to cause the impeller assembly 116A tocollapse. This provides an outer profile throughout the catheterassembly and catheter pump 100A that is of small diameter duringinsertion, for example, to a catheter size of about 12.5 FR in variousarrangements. In other embodiments, the impeller assembly 116A is notexpandable.

The mechanical components rotatably supporting the impeller within theimpeller assembly 116A permit relatively high rotational speeds whilecontrolling heat and particle generation that can come with high speeds.The infusion system delivers a cooling and lubricating solution to thedistal portion of the catheter pump 100A for these purposes. The spacefor delivery of this fluid is extremely limited. Some of the space isalso used for return of the fluid supplied to the patient as wastefluid. Providing secure connection and reliable routing of the suppliedfluid into and out of the catheter pump 100A is critical and challengingin view of the small profile of the catheter assembly.

When activated, the catheter pump 100A can effectively support, restoreand/or increase the flow of blood out of the heart and through thepatient's vascular system. In various embodiments disclosed herein, thepump 100A can be configured to produce a maximum flow rate (e.g. low mmHg) of greater than 4 Lpm, greater than 4.5 Lpm, greater than 5 Lpm,greater than 5.5 Lpm, greater than 6 Lpm, greater than 6.5 Lpm, greaterthan 7 Lpm, greater than 7.5 Lpm, greater than 8 Lpm, greater than 9Lpm, or greater than 10 Lpm. In various embodiments, the pump 100A canbe configured to produce an average flow rate at 62 mmHg of greater than2 Lpm, greater than 2.5 Lpm, greater than 3 Lpm, greater than 3.5 Lpm,greater than 4 Lpm, greater than 4.25 Lpm, greater than 4.5 Lpm, greaterthan 5 Lpm, greater than 5.5 Lpm, or greater than 6 Lpm.

Various aspects of the pump and associated components can be combinedwith or substituted for those disclosed in U.S. Pat. Nos. 7,393,181;8,376,707; 7,841,976; 7,022,100; and 7,998,054, and in U.S. Pub. Nos.2011/0004046; 2012/0178986; 2012/0172655; 2012/0178985; and2012/0004495, the entire contents of each of which are incorporatedherein for all purposes by reference. In addition, this applicationincorporates by reference in its entirety and for all purposes thesubject matter disclosed in each of the following applications: U.S.Patent Publication No. US 2013/0303970, entitled “DISTAL BEARINGSUPPORT,” filed on Mar. 13, 2013; U.S. Patent Publication No. US2014/0275725, entitled “FLUID HANDLING SYSTEM,” filed on Mar. 11, 2014;U.S. Patent Publication No. US 2013/0303969, entitled “SHEATH SYSTEM FORCATHETER PUMP,” filed on Mar. 13, 2013; U.S. Patent Publication No. US2013/0303830, entitled “IMPELLER FOR CATHETER PUMP,” filed on Mar. 13,2013; U.S. Patent Publication No. US 2014/0012065, entitled “CATHETERPUMP,” filed on Mar. 13, 2013; and U.S. Patent Publication No. US2014/0010686, entitled “MOTOR ASSEMBLY FOR CATHETER PUMP,” filed on Mar.13, 2013.

Moving from a distal end 1450 of the catheter assembly of the catheterpump 100A of FIG. 1B to a proximal end 1455, a priming apparatus 1400can be disposed over the impeller assembly 116A. As explained above, theimpeller assembly 116A can include an expandable cannula or housing andan impeller with one or more blades. As the impeller rotates, blood canbe pumped proximally (or distally in some implementations) to functionas a cardiac assist device.

In FIG. 1B the priming apparatus 1400 can be disposed over the impellerassembly 116A near the distal end portion 170A of the elongate body174A. The priming apparatus 1400 can be used in connection with aprocedure to expel air from the impeller assembly 116A, e.g., any airthat is trapped within the housing or that remains within the elongatebody 174A near the distal end 170A. For example, the priming proceduremay be performed before the pump is inserted into the patient's vascularsystem, so that air bubbles are not allowed to enter and/or injure thepatient. The priming apparatus 1400 can include a primer housing 1401configured to be disposed around both the elongate body 174A and theimpeller assembly 116A. A sealing cap 1406 can be applied to theproximal end 1402 of the primer housing 1401 to substantially seal thepriming apparatus 1400 for priming, i.e., so that air does notproximally enter the elongate body 174A and also so that priming fluiddoes not flow out of the proximal end of the housing 1401. The sealingcap 1406 can couple to the primer housing 1401 in any way known to askilled artisan. In some embodiments, the sealing cap 1406 is threadedonto the primer housing by way of a threaded connector 1405 located atthe proximal end 1402 of the primer housing 1401. The sealing cap 1406can include a sealing recess disposed at the distal end of the sealingcap 1406. The sealing recess can be configured to allow the elongatebody 174A to pass through the sealing cap 1406.

The priming operation can proceed by introducing fluid into the sealedpriming apparatus 1400 to expel air from the impeller assembly 116A andthe elongate body 174A. Fluid can be introduced into the primingapparatus 1400 in a variety of ways. For example, fluid can beintroduced distally through the elongate body 174A into the primingapparatus 1400. In other embodiments, an inlet, such as a luer, canoptionally be formed on a side of the primer housing 1401 to allow forintroduction of fluid into the priming apparatus 1400. A gas permeablemembrane can be disposed on a distal end 1404 of the primer housing1401. The gas permeable membrane can permit air to escape from theprimer housing 1401 during priming.

The priming apparatus 1400 also can advantageously be configured tocollapse an expandable portion of the catheter pump 100A. The primerhousing 1401 can include a funnel 1415 where the inner diameter of thehousing decreases from distal to proximal. The funnel may be gentlycurved such that relative proximal movement of the impeller housingcauses the impeller housing to be collapsed by the funnel 1415. Duringor after the impeller housing has been fully collapsed, the distal end170A of the elongate body 174A can be moved distally relative to thecollapsed housing. After the impeller housing is fully collapsed andretracted into the elongate body 174A of the sheath assembly, thecatheter pump 100A can be removed from the priming housing 1400 before apercutaneous heart procedure is performed, e.g., before the pump 100A isactivated to pump blood. The embodiments disclosed herein may beimplemented such that the total time for infusing the system isminimized or reduced. For example, in some implementations, the time tofully infuse the system can be about six minutes or less. In otherimplementations, the time to infuse can be about three minutes or less.In yet other implementations, the total time to infuse the system can beabout 45 seconds or less. It should be appreciated that lower times toinfuse can be advantageous for use with cardiovascular patients.

With continued reference to FIG. 1B, the elongate body 174A extends fromthe impeller assembly 116A in a proximal direction to an fluid supplydevice 195. The fluid supply device 195 is configured to allow for thesupplied fluid to enter the catheter assembly 100A and/or for wastefluid to leave the catheter assembly 100A. A catheter body 120A (whichalso passes through the elongate body 174A) can extend proximally andcouple to the motor assembly 1. As discussed in more detail herein, themotor assembly 1 can provide torque to a drive shaft that extends fromthe motor assembly 1 through the catheter body 120A to couple to animpeller shaft at or proximal to the impeller assembly 116A. Thecatheter body 120A can pass within the elongate body 174A such that theexternal elongate body 174A can axially translate relative to theinternal catheter body 120A.

Further, as shown in FIG. 1B, a fluid supply line 6 can fluidly couplewith the console 122 to supply saline or other fluid to the catheterpump 100A. The saline or other fluid can pass through an internal lumenof the internal catheter body 120A and can provide lubrication to theimpeller assembly 116A and/or chemicals to the patient. The suppliedfluid (e.g., saline or glucose solution) can be supplied to the patientby way of the catheter body 120 at any suitable flow rate. For example,in various embodiments, the fluid is supplied to the patient at a flowrate in a range of 15 mL/hr to 50 mL/hr, or more particularly, in arange of 20 mL/hr to 40 mL/hr, or more particularly, in a range of 25mL/hr to 35 mL/hr. One or more electrical conduits 124 can provideelectrical communication between the console 122 and the motor assembly1. A controller within the console 122 can control the operation of themotor assembly 1 during use.

In addition, a waste line 7 can extend from the motor assembly 1 to awaste reservoir 126. Waste fluid from the catheter pump 100A can passthrough the motor assembly 1 and out to the reservoir 126 by way of thewaste line 7. In various embodiments, the waste fluid flows to the motorassembly 1 and the reservoir 126 at a flow rate which is lower than thatat which the fluid is supplied to the patient. For example, some of thesupplied fluid may flow out of the catheter body 120 and into thepatient by way of one or more bearings. The waste fluid (e.g., a portionof the fluid which passes proximally back through the motor from thepatient) may flow through the motor assembly 1 at any suitable flowrate, e.g., at a flow rate in a range of 5 mL/hr to 20 mL/hr, or moreparticularly, in a range of 10 mL/hr to 15 mL/hr.

Access can be provided to a proximal end of the catheter assembly of thecatheter pump 100A prior to or during use. In one configuration, thecatheter assembly 101 is delivered over a guidewire 235. The guidewire235 may be conveniently extended through the entire length of thecatheter assembly 101 of the catheter pump 100A and out of a proximalend 1455 of the catheter assembly 101. In various embodiments, theconnection between the motor assembly 1 and the catheter assembly 101 isconfigured to be permanent, such that the catheter pump, the motorhousing and the motor are disposable components. However, in otherimplementations, the coupling between the motor housing and the catheterassembly is disengageable, such that the motor and motor housing can bedecoupled from the catheter assembly after use. In such embodiments, thecatheter assembly distal of the motor can be disposable, and the motorand motor housing can be re-usable.

In addition, FIG. 1B illustrates the guidewire 235 extending from aproximal guidewire opening 237 in the motor assembly 1. Before insertingthe catheter assembly 101 of the catheter pump 100A into a patient, aclinician may insert the guidewire 235 through the patient's vascularsystem to the heart to prepare a path for the impeller assembly 116A tothe heart. In some embodiments, the catheter pump 100A can include aguidewire guide tube 20 (see FIG. 3) passing through a central internallumen of the catheter pump 100A from the proximal guidewire opening 237.The guidewire guide tube 20 can be pre-installed in the catheter pump100A to provide the clinician with a preformed pathway along which toinsert the guidewire 235.

In one approach, the guidewire 235 is first placed through a needle intoa peripheral blood vessel, and along the path between that blood vesseland the heart and into a heart chamber, e.g., into the left ventricle.Thereafter, a distal end opening of the catheter pump 100A and guidewireguide tube 20 can be advanced over the proximal end of the guidewire 235to enable delivery to the catheter pump 100A. After the proximal end ofthe guidewire 235 is urged proximally within the catheter pump 100A andemerges from the guidewire opening 237 and/or guidewire guide 20, thecatheter pump 100A can be advanced into the patient. In one method, theguidewire guide 20 is withdrawn proximally while holding the catheterpump 100A.

Alternatively, the clinician can thus insert the guidewire 235 throughthe proximal guidewire opening 237 and urge the guidewire 235 along theguidewire guide tube 20. The clinician can continue urging the guidewire235 through the patient's vascular system until the distal end of theguidewire 235 is positioned in the desired position, e.g., in a chamberof the patient's heart, a major blood vessel or other source of blood.As shown in FIG. 1B, a proximal end portion of the guidewire 235 canextend from the proximal guidewire opening 237. Once the distal end ofthe guidewire 235 is positioned in the heart, the clinician can maneuverthe impeller assembly 116A over the guidewire 235 until the impellerassembly 116A reaches the distal end of the guidewire 235 in the heart,blood vessel or other source of blood. The clinician can remove theguidewire 235 and the guidewire guide tube 20. The guidewire guide tube20 can also be removed before or after the guidewire 235 is removed insome implementations.

After removing at least the guidewire 235, the clinician can activatethe motor 1 to rotate the impeller and begin operation of the pump 100A.

FIG. 2A is a side plan view of the motor assembly 1 shown in FIG. 1B,according to one embodiment. FIGS. 2B-2C are side plan views of themotor assembly 1 shown in FIG. 1B, according to other embodiments. FIG.3 is a perspective exploded view of the motor assemblies 1 shown inFIGS. 2A-2C. The motor assembly 1 can include a stator assembly 2 and arotor 15 disposed radially within the stator assembly 2. The motorassembly 1 also includes a flow diverter 3, which can be configured as amanifold for directing fluid through one or more passages in thecatheter pump 100A. In some embodiments, the flow diverter 3 is at leastpartially disposed radially between the stator assembly 2 and the rotor15. The flow diverter 3 can be fluidly sealed about the rotor 15 and aproximal portion 56 of the catheter body 120A. The seal prevents leakageand also can prevent the fluid from contacting the stator assembly 2.The flow diverter 3 can include a distal chamber 5 within which theproximal portion 56 of the catheter body 120A is disposed and a rotorchamber 4 within which the rotor 15 is disposed. The flow diverter 3 canalso have a proximal chamber 10 in some embodiments. Where provided, thedistal chamber 5, rotor chamber 4, and proximal chamber 10 can be influid communication within the flow diverter 3. In the illustratedembodiments, the distal chamber 5, the rotor chamber 4, and the proximalchamber 10 can be manufactured as three separate components and can bemechanically joined together to form the flow diverter 3. A first gasket(e.g., o-ring) 31 can be provided between the proximal chamber 10 andthe rotor chamber 4 to fluidly seal the proximal chamber 10 and therotor chamber 4. A second gasket 32 (e.g., o-ring) can be providedbetween the rotor chamber 4 and the distal chamber 5 to fluidly seal theconnection between the rotor chamber 4 and the distal chamber 5. The useof the gaskets 31, 32 can simplify manufacturing and sealing comparedwith implementations in which the seals are formed by applying anadhesive about the periphery of the joined components. Thus, the firstgasket 31 can prevent fluid from leaking outside the proximal chamber10, e.g., at an interface between the proximal chamber 10 and the rotorchamber 4. The second gasket 32 can prevent fluid from leaking outsidethe distal chamber 5, e.g., at an interface between the distal chamber 5and the rotor chamber 4.

One or more flanges 11A, 11B can mechanically couple the flow diverter 3to an external housing (not shown). The flanges 11A, 11B are examples ofmount structures that can be provided, which can include in variousembodiments dampers to isolate the motor assembly 1 from external shockor vibration. In some embodiments, mount structures can include dampersconfigured to isolate an outer housing or the environment external tothe motor assembly 1 from shock or vibration generated by the motorassembly 1. In addition, the guidewire guide tube 20 can extendproximally through the motor assembly 1 and can terminate at a tube endcap 8. As explained above, the guidewire 235 can be inserted within theguide tube 20 for guiding the catheter pump 100A to the heart.

The rotor 15 and stator assembly 2 can be configured as or be componentsof a frameless-style motor for driving the impeller assembly 116A at thedistal end of the pump 100A. For example, the stator assembly 2 cancomprise a stator and a plurality of conductive windings producing acontrolled magnetic field. The rotor 15 can comprise a magneticmaterial, e.g., can include one or more permanent magnets. In someembodiments, the rotor 15 can comprise a multi-pole magnet, e.g., afour-pole or six-pole magnet. Providing changing electrical currentsthrough the windings of the stator assembly 2 can create magnetic fieldsthat interact with the rotor 15 to cause the rotor 15 to rotate. This iscommonly referred to as commutation. The console 122 can provideelectrical power (e.g., 24V) to the stator assembly 2 to drive the motorassembly 1. One or more leads can electrically communicate with thestator assembly 2, e.g., with one or more Hall sensors used to detectthe speed and/or position of the motor. In other embodiments, othersensors (e.g., optical sensors) can be used to measure motor speed. Therotor 15 can be secured to an output shaft 13 (which can comprise ahollow shaft with a central lumen) such that rotation of the rotor 15causes the output shaft 13 to rotate. In various embodiments, the motorassembly 1 can comprise a direct current (DC) brushless motor. In otherembodiments, other types of motors can be used, such as AC motors, etc.As shown in FIG. 3, first and second journal bearings 18A, 18B can beprovided about the output shaft 13 to radially and/or longitudinallycenter the output shaft 13 and thereby the rotor 15 relative to thestator assembly 2.

In various embodiments, it can be important to provide a heat removalsystem to limit buildup of heat in the motor assembly 1 duringoperation. For example, it can be important to maintain externalsurfaces of the motor assembly 1 at a temperature less than about 40° C.if the motor assembly 1 is positioned near the patient. For example, anexternal surface of an external housing 40 of the motor assembly 1 maybe kept at or below this temperature. In some respects, regulatoryguidelines can require that no part in contact with skin exceed 40 ° C.To that end, various strategies for heat management are employed by theinventions described herein. It should be appreciated that, as usedherein, cooling refers to transferring away or dissipating heat, and incertain respects, cooling is used interchangeably with removing heat.Advantageously, some embodiments disclosed herein can utilize a heatremoval system comprising one or more thermal layers which direct heataway from the heat-generating component (i.e., motor assembly 1) toreduce the temperature thereof. The one or more thermal layers mayutilize waste fluid returning from the patient to remove heat in someembodiments. In other embodiments, the one or more thermal layers may besupplied with a coolant, such as a liquid or gaseous coolant, to coolthe components of the motor assembly 1 and dissipate heat. In theembodiment illustrated in FIGS. 2A-3, for example, the thermal layer cancomprise a heat exchanger 30, e.g., a coil which can be disposed aboutthe stator assembly 2. For example, the coil of the heat exchanger 30can be wrapped about a portion of the stator assembly 2 and can bedisposed within a motor housing. In one embodiment, the heat exchanger30 comprises a tubular body having a lumen. The tubular body and thelumen have a helical configuration where the inner dimeter of the helixis larger than the outer diameter of the stator assembly. The tubularbody and the lumen can have an outer dimeter that is smaller than theinner periphery of the housing 40, discussed in more detail below. Thecoils of the helix can be tightly packed along a longitudinal axis ofthe helix, preferably close together but not touching. For example,adjacent centers of the lumen of the tubular body can be spaced apart by110% of the outside diameter of the tubular body. As shown in FIGS.2A-2C, the heat exchanger 30 can be axially positioned between adistal-most end of the stator assembly 2 and a proximal-most end of thestator assembly 2. Thus, the heat exchanger can comprise a volume toreceive fluid for cooling the motor assembly. The volume of the heatexchanger to receive fluid can comprise an inner lumen of a coiled tube.In some embodiments, the volume of the heat exchanger to receive fluidcan comprise a hollow portion of an annular cylinder, sleeve or jacket.The heat exchanger can be disposed about the stator in variousembodiments disclosed herein.

Although the heat exchanger 30 is illustrated as a coiled lumen, e.g.,as a helix, in FIGS. 2A-3, in other embodiments, the heat exchanger 30can comprise an annular cylinder disposed about the stator assembly 2.For example, FIG. 3A is a schematic view of a heat exchanger 30A whichmay be used in any of the embodiments disclosed herein. The heatexchanger 30A can be shaped as an annular cylinder sized to be disposedabout the stator assembly. Fluid can pass through the wall of theannular cylinder to dissipate heat from the motor assembly. In variousembodiments, the heat exchanger 30 can comprise a jacket (e.g., a waterjacket) or any other device which is at least partially disposed aboutthe stator assembly 2. In various embodiments, the heat exchangercomprises one or more thermal layers such as those disclosed in U.S.App. No. 13/953,547, filed Jul. 29, 2013, the entire contents of whichapplication are incorporated by reference herein for all purposes.

The output shaft 13 (which is secured to the rotor 15) can bemechanically coupled with the proximal end portion of a drive shaft 16.The drive shaft 16 can extend distally through an internal lumen of thecatheter body 120A. A distal end portion of the drive shaft 16 canmechanically connect with the impeller. Thus, rotation of the rotor 15can cause the output shaft 13 to rotate, which, in turn, can cause thedrive shaft 16 and the impeller to rotate. Further, a lumen can extendthrough the output shaft 13 and the rotor 15. In certain embodiments,the lumen of the rotor 15 is coupled with a lumen of the catheter body120A such that the guidewire guide tube 20 can extend through the lumenwithin the rotor 15 and into the lumen of the catheter body 120A. Inaddition, the drive shaft 16 comprises a braided shaft having aninternal lumen. The braided drive shaft 16 or cable can be permeable toliquid that can flow from outside the drive shaft 16 to within theinternal lumen of the drive shaft 16 (and vice versa).

Further, as shown in FIGS. 2A-3, the tube end cap 8 can be welded orotherwise secured to a proximal end portion of the guide tube 20. Thecap 8 can be removably engaged (e.g., screwed or removably locked) overa female receiver 71 that is secured in a proximal end of the proximalchamber 10. For example, the proximal end of the female receiver 71 canbe disposed in a counterbore of the cap 8, while the guide tube 20extends through the central opening of the cap 8. In a lockedconfiguration, one or more tabs of the receiver 71 can be rotated suchthat the tab(s) slide under a corresponding tab in the counterbore ofthe cap 8. In an unlocked configuration, the tab(s) of the receiver 71can be rotated relative to the tabs of the cap 8. FIG. 6 shows oneembodiment of the cap 8 and of the female receiver 71 that can becoupled with the guide tube 20 (not shown). In the illustratedembodiment, the cap 8 can be fixed to the guide tube 20; in otherembodiments, the receiver 71 can be fixed to the guide tube 20. Engagingthe cap 8 to the receiver 71 can advantageously prevent the guide tube20 from accidentally being removed from or slid within the catheter pump100A, e.g., if the patient or clinician impacts the cap 8. To remove theguide tube 20 (e.g., after delivery of the impeller assembly 116A to theheart), the clinician can disengage the cap 8 from the receiver 71 andcan pull the guide tube 20 from the catheter pump 100A, for example, bypulling proximally on the end cap 8. A resealable septum 72 can beprovided at the proximal end of the flow diverter 3. When the guidewireguide 20 is removed from the pump 100A, the septum 72 will naturallyreseal the pathway proximally from the motor assembly 1 such that fluiddoes not exit the assembly 1. An advantage of the exemplary assemblydescribed herein is that the cap 8 is locked such that it will not bedislodged without rotating and unlocking cap 8 from receiver 71. With aconventional torquer assembly, the cap 8 can slide axially if it isinadvertently bumped by the patient or clinician. This potentiallyresults in the guide tube 20 being pulled out from the distal-most endof the impeller assembly 116A, and because the guide tube cannot bere-inserted, the clinician either has to use the catheter pump 100Awithout a guide or get a new pump.

As explained above, it can be important to ensure that the motorassembly 1 is adequately cooled. Various components of the motorassembly 1 can generate heat. For example, moving parts within the motorassembly 1 (e.g., the rotating output shaft 13 and/or drive shaft 16)can generate heat by virtue of losses through friction, vibrations, andthe like, which may increase the overall temperature of the motorassembly 1. Further, heat can be generated by the electrical currentflowing through the stator assembly 2 and/or by induction heating causedby conductive components inside a rotating magnetic field. Furthermore,friction between the bearings 18 and the output shaft 13 and/or frictionbetween the drive shaft 16 and the inner wall of catheter body 120A mayalso generate undesirable heat in the motor assembly. Inadequate coolingcan result in temperature increases of the motor assembly 1, which canpresent patient discomfort, health risks, or performance losses. Thiscan lead to undesirable usage limitations and engineering complexity,for example, by requiring mitigation for differential heat expansion ofadjacent components of different materials. Accordingly, variousembodiments disclosed herein can advantageously transfer away generatedheat and cool the motor assembly 1 such that the operating temperatureof the assembly 1 is sufficiently low to avoid such complexities of useor operation and/or other components of the system. For example, variousheat transfer components and/or thermal layers can be used to move heataway from thermal generation sources and away from the patient. Variousaspects of the illustrated device herein are designed to reduce the riskof hot spots, reduce the risk of heat spikes, and/or improve heatdissipation to the environment and away from the patient.

FIG. 2A illustrates an example of one embodiment for cooling the motorassembly 1. As shown in FIG. 2A, the supply line 6 can provide fluid 35from a source (e.g., a fluid bag) to an outer lumen 57 of the catheterbody 120A. The fluid 35 can travel distally toward the impeller assembly116A to lubricate rotating components in the catheter assembly 101and/or supply fluid to the patient. A first seal 37 (e.g., an o-ring) isan example of a fluid barrier that can be provided between the rotorhousing 4 and the distal housing 5 to prevent backflow of the fluid 35into the rotor housing 4. In this context, backflow is flow of fluid 35proximally into the distal housing 5 rather than distally within thelumen 57. Such flow is to be prevented to ensure that the fluid 35 isinitially exposed to moving parts in a distal portion of the catheterassembly 101 to lubricate and cool such distal components. A second seal38 (e.g., an o-ring) is an example of another fluid barrier that can beprovided near a distal opening of the distal chamber 5 to prevent fluid35 from leaking outside the flow diverter 3 (e.g., out of the distalchamber 5).

A first portion 17 a of fluid from the catheter pump 100A can flowproximally through an inner lumen 58 of the catheter body 120A. Forexample, after initially cooling distal components, some or all of thefluid 35 can flow within the drive shaft 16 and/or around the peripheryof the drive shaft 16. After initially cooling distal components some orall of the fluid 35 can flow in a space disposed radially between thedrive shaft 16 and the catheter body 120A. As shown in FIG. 2A, thecooling fluid 17 a can flow into the rotor chamber 4 of the flowdiverter 3. Some portions of the fluid 17 a can pass proximally throughthe motor assembly 1 about a periphery of the rotor 15, e.g., in a gapbetween the rotor 15 and a wall of the flow diverter 3. In someembodiments, other portions of the fluid 17 a can pass proximallythrough the motor assembly 1 through a lumen of the output shaft 13. Thefluid portion 17 a can pass from the rotor chamber 4 into the proximalchamber 10 of the flow diverter 3. The fluid 17 a that passes proximallythrough the rotor chamber 4 (e.g., the portions that flow about theperiphery of the rotor 15 and/or the portions that pass through thelumen of the output shaft 13) can advantageously convey heat away fromthe heat generating components. For example, portions of the coolingfluid 17 a that pass about the periphery of the rotor 15 can direct heatradially outward from the rotor 15 and other components of the flowdiverter 3, and radially inward from the stator assembly 2 and othercomponents outside the flow diverter 3. Portions of the fluid 17 a thatpass through the lumen of the output shaft 13 can draw heat radiallyinward, e.g., radially inward from the rotor 15 and other components ofthe flow diverter 3. As the heat from the motor assembly 1 is conveyedaway by way of the fluid to the waste reservoir, the temperature of themotor housing 1 can be reduced or maintained at a safe temperature forthe patient and/or for the catheter pump system.

Thermal management of the motor assembly 1 can be improved by directingfluid through the heat exchanger 30. For example, in the embodiment ofFIG. 2A, a second portion 17 b of the fluid can pass through the line 7and can be directed by a conduit to an inlet of the heat exchanger 30. Athird portion 17 c of the fluid can flow through the heat exchanger 30circumferentially about the stator assembly 2. A fourth portion 17 d ofthe fluid can flow through an outlet of the heat exchanger 30 and intothe waste reservoir 126. Heat generated by the motor assembly 1 can bedirected radially outward from the stator assembly 2, the rotor chamber4, and/or other heat generating components of the motor assembly 1, andcan be conveyed away by the fluid 17 c that flows through the heatexchanger 30 (e.g., within tubing or coils thereof). Thus, theembodiment of FIG. 2A can advantageously reduce the operatingtemperature of the motor assembly 1 to maintain the temperature of themotor assembly 1 at a suitable operational temperature for the medicalstaff, the patient and/or for the catheter pump system. Furthermore,although the heat exchanger 30 illustrated in FIG. 2A comprises coiledtubing, in other embodiments, the heat exchanger 30 can comprise anannular cylinder or other type of jacket which is disposed at leastpartially around the stator assembly 2. Like the illustrated embodiment,the use of a jacket or other type of heat exchanger can cool the motorassembly 1 by drawing heat radially outward from the components of themotor assembly 1. In the case where the motor assembly is resting nearor against the patient, a jacket can also advantageously shield thepatient from heat generated within the assembly to avoid injury anddiscomfort.

In the embodiment of FIG. 2A, the motor assembly 1 can comprise a fluidpathway for the proximally-flowing fluid 17 a-17 d to dissipate heataway from the motor assembly 1. For example, the fluid pathway cancomprise a first portion through which the first fluid portion 17 aflows (e.g., within the flow diverter 3). The fluid pathway can comprisea second portion comprising a conduit or tube which connects the firstportion to the inlet of the heat exchanger 30 and through which thesecond fluid portion 17 b flows. The fluid pathway can comprise a thirdportion comprising the heat exchanger 30 and through which the thirdfluid portion 17 c flows. The fluid pathway can comprise a fourthportion comprising a conduit or tubing connected to the waste reservoir126 and through which the fourth fluid portion 17 d flows.

FIG. 2B illustrates an example of another embodiment for cooling themotor assembly 1. Unless otherwise noted, components numbered similar tothose in FIG. 2A represent the same or similar components andfunctionalities. For example, a first fluid portion 35 a (e.g., saline)can flow along the supply line 6 and can be directed distally through anouter lumen 57 of the catheter body 120A. The first portion 35 a cancomprise saline, glucose, or other biocompatible fluids in variousarrangements. A first portion 17 a of the proximally-flowing fluid canreturn proximally through an inner lumen 58 of the catheter body 120A.The fluid 17 a can flow within the drive shaft 16 and/or around theperiphery of the drive shaft 16. As shown in FIG. 2B, the fluid 17 a canflow into the rotor chamber 4 of the flow diverter 3. Some portions ofthe fluid 17 a can pass proximally through the motor assembly 1 about aperiphery of the rotor 15, e.g., in a gap between the rotor 15 and awall of the flow diverter 3. Other portions of the fluid 17 a can passproximally through the motor assembly 1 through the lumen of the outputshaft 13. The fluid 17 a can pass from the rotor chamber 4 into theproximal chamber 10 of the flow diverter 3. The fluid 17 a that passesproximally through the rotor chamber 4 (e.g., the portions that flowabout the periphery of the rotor 15 and/or the portions that passthrough the lumen of the output shaft 13) can advantageously convey heataway from the heat generating components. For example, portions of thefluid 17 a that pass about the periphery of the rotor 15 can direct heatradially outward from the rotor 15 and other components of the flowdiverter 3, and radially inward from the stator assembly 2 and othercomponents outside the flow diverter 3. Portions of the fluid 17 a thatpass through the lumen of the output shaft 13 can draw heat radiallyinward, e.g., radially inward from the rotor 15 and other components ofthe flow diverter 3. As the heat from the motor assembly 1 is conveyedaway by way of the fluid to the waste reservoir, the temperature of themotor housing 1 can be reduced or maintained at a safe temperature forthe patient and/or for the catheter pump system.

Unlike the embodiment of FIG. 2A, in the embodiment of FIG. 2B, a secondportion 17 b of the proximally-flowing cooling fluid can be directed tothe waste reservoir 126 by way of the waste line 7. Thus, in FIG. 2B,the fluid 17 b is not redirected into the heat exchanger 30. Instead, asecond fluid portion 35 b is directed into an inlet of the heatexchanger 30. A third fluid portion 35 c can flow through the heatexchanger 30 circumferentially about the stator assembly 2. A fourthfluid portion 35 d can flow through an outlet of the heat exchanger 30and into the waste reservoir 126. The coolant that flows through thefluid portions 35 a, 35 b, 35 c, and 35 d can be saline or anothercoolant that need not be biocompatible. Heat generated by the motorassembly 1 can be directed radially outward from the stator assembly 2,the rotor chamber 4, and/or other heat generating components of themotor assembly 1, and can be conveyed away by the third fluid portion 35c that flows within the tubing of the heat exchanger 30. Thus, theembodiment of FIG. 2B can advantageously reduce the operatingtemperature of the motor assembly 1 such that temperature of the motorassembly is maintained at a suitable operational temperature for themedical staff, the patient and/or for the catheter pump system. A gapbetween the stator assembly and the external motor housing 40 (e.g., theouter shell or housing surrounding the motor assembly) comprises air,which is a good, natural insulator. Thus, the heat from the statorassembly 2 is naturally transferred to the waste line rather thandissipating out the sides of the housing 40 of the motor assembly 1.

Although the fluid 35 is described as comprising saline in someembodiments, it should be appreciated that other fluids (such asrefrigerants, e.g., R134) can be used within the heat exchanger 30. Forexample, in other embodiments, a first portion 39 a of a cooling fluid39 other than the supply fluid (e.g., other than saline) can be suppliedto an inlet of the heat exchanger 30. A second portion 39 b of thecooling fluid can pass through the heat exchanger 30 to draw heat awayfrom the motor assembly. A third portion 39 c of the cooling fluid canbe conveyed through an outlet of the heat exchanger 30 and into thewaste reservoir 126. The cooling fluid 39 can comprise any suitable typeof fluid, e.g., any suitable cooling liquid or gas. For example, in someembodiments, the cooling fluid 39 can comprise a refrigerant such asR134A can be used. In other embodiments, water or another liquid may beused as the cooling fluid 39. In still other embodiments, the coolingfluid 39 can comprise a gas, such as air, nitrogen, etc. For example, insome embodiments, the cooling fluid 39 can comprise air supplied bypressurized air systems that are frequently available in hospitals andother clinical settings. The use of such conventional pressurized airsystems can advantageously reduce the number of external supplyreservoirs provided with the catheter pump system, which can reducecosts and simplify packaging. Furthermore, a chiller or other coolingapparatus can be provided upstream of the heat exchanger 30 to cool thesupplied fluid 35 and/or cooling fluid 39 prior to the fluid 35 and/orcooling fluid 39 entering the heat exchanger 30. Cooling the fluid 35and/or cooling fluid 39 can advantageously improve the thermalmanagement of the motor assembly 1. Advantageously, using a coolingfluid 39 which is different from the fluid 35 supplied to the patientmay reduce the temperature to a greater degree than using the fluid 35alone. For example, the cooling fluid 39 may have superior heat transferqualities relative to the fluid 35.

In the embodiment of FIG. 2B, the motor assembly 1 can comprise a firstfluid pathway for the fluid 35 a supplied to the patient, a second fluidpathway for the proximally-flowing fluid 17 a-17 b, and a third fluidpathway for the fluid supplied to the heat exchanger (e.g., the fluid 35b-d or 39 a-c). For example, the first fluid pathway can comprise aconduit in fluid communication with an inner lumen of the catheter bodywhich travels distally tot he treatment location. The second fluidpathway can comprise a first portion through which the first fluidportion 17 a flows (e.g., within the flow diverter 3) and a secondportion through which the fluid portion 17 b flows to the wastereservoir 126. The third fluid pathway can comprise a first portioncomprising a tube or conduit which conveys the fluid 35 b, 39 a to theinlet of the heat exchanger 30 and a second portion comprising the heatexchanger 30 and through which the fluid portion 35 c, 39 b flows. Thethird fluid pathway can comprise a third portion comprising a conduit ortubing connected to the waste reservoir 126 and through which the fluidportion 35 d, 39 c flows.

FIG. 2C illustrates yet an example of another embodiment for cooling themotor assembly 1. Unless otherwise noted, components numbered similar tothose in FIG. 2A represent the same or similar components andfunctionalities. For example, as with the embodiment of FIG. 2A, a firstportion 17 a of the proximally-flowing fluid can pass within the motorassembly 1, for example, about a periphery of the rotor 15, e.g., in agap between the rotor 15 and a wall of the flow diverter 3. In someembodiments, other portions of the fluid 17 a can pass proximallythrough the motor assembly 1 through a lumen of the output shaft 13. Inthe embodiment of FIG. 2A, the fluid is directed to the heat exchanger30 after passing through the flow diverter 3. Unlike the embodiment ofFIG. 2A, in the embodiment of FIG. 2C, a second portion 17 b of theproximally-flowing fluid can be shunted from the flow diverter 3 beforepassing within and/or around the rotor 15. For example, an outlet linecan direct the second portion 17 b of the fluid out of the flow diverter3 and to the inlet of the heat exchanger 30. A third portion 17 c of thefluid can pass through the heat exchanger 30 to draw heat radiallyoutward from the stator assembly 2 and other components of the motorassembly 1. A fourth portion 17 d of the fluid can be conveyed to thewaste reservoir 126. Furthermore, unlike the embodiment of FIG. 2A, inthe embodiment of FIG. 2C, the first portion 17 a of the fluid can bedirected to the waste reservoir 126 after passing through the flowdiverter 3.

In the embodiment of FIG. 2C, the motor assembly 1 can comprise a fluidpathway for the proximally-flowing fluid 17 a-17 d to dissipate heataway from the motor assembly 1. For example, the fluid pathway cancomprise a first portion through which the fluid portion 17 a flows(e.g., within the flow diverter 3). The fluid pathway can comprise asecond portion which splits off from the first portion of the fluidpathway and comprises a conduit or tube which connects to the inlet ofthe heat exchanger 30 and through which the second fluid portion 17 bflows. The fluid pathway can comprise a third portion comprising theheat exchanger 30 and through which the third fluid portion 17 c flows.The fluid pathway can comprise a fourth portion comprising a conduit ortubing connected to the waste reservoir 126 and through which the fourthfluid portion 17 d flows.

Still other thermal management techniques may be suitable in combinationwith the embodiments disclosed herein. For example, U.S. PatentPublication Nos. 2014/0031606 and 2011/0295345, which are incorporatedby reference herein in their entirety and for all purposes, describestructures and materials which may be incorporated in place of or inaddition to the devices described above to manage heat effectively, aswill be understood by one of skill from the description herein.Furthermore, as explained herein, the heat exchanger 30 can comprise anysuitable shape or configuration. For example, the heat exchanger 30 cancomprise a jacket (such as an annular cylinder or sleeve) disposed aboutthe stator assembly 2 in some embodiments. In some embodiments, thesystems disclosed in FIGS. 1A-4 can ensure that the temperature of theexterior surface of the motor assembly 1 is not more than about 40 ° C.In some embodiments, the systems disclosed in FIGS. 1A-4 can ensure thatthe temperature of the exterior surface of the motor assembly 1 is in arange of 15° C. to 42° C., or more particularly in a range of 20° C. to42° C., in a range of 20° C. to 40° C., in a range of 20° C. to 35° C.,or in a range of 20° C. to 30° C., without requiring the use of externalcooling fins exposed outside the motor housing.

Operation of the motor assembly 1 may also generate undesirablevibrations. For example, high magnitude vibrations can be inconvenientfor the patient or clinician, and/or can damage components of the motorassembly 1. One way that vibrations are reduced and controlled in thedisclosed embodiments is by providing the journal bearings 18A, 18B(FIG. 3) on opposite axial sides of the rotor 15 to help maintain therotor 15 in radial alignment with the rotor chamber 4 and in axialalignment with the stator assembly 2. Improving radial alignment of therotor 15 and output shaft 13 relative to the rotor chamber 4 can reduceor eliminate eccentricity during rotation, which can reduce vibrations.Improving axial alignment relative to the stator assembly 2 canadvantageously improve the efficiency of the motor assembly 1 byensuring that the windings of the stator assembly 2 remain preciselyaligned with the rotor 15. In various embodiments, the journal bearings18A, 18B can be rotationally decoupled with the output shaft 13 suchthat the output shaft 13 can rotate relative to the bearings 18A, 18B.In some embodiments, the journal bearings 18A, 18B can be fixed insidethe rotor chamber 4. Moreover, one or more passages can be provided inthe bearings 18A, 18B so that cooling fluid can pass axially through thebearings 18A, 18B. For example, the bearings 18A, 18B can formradially-extending arms with one or more gaps disposed between the arms.Such gaps can be enclosed peripherally by a housing enclosing the statorassembly 2. In other embodiments, one or more openings can be providedthrough the bearings 18A, 18B to define the passages. Furthermore, byusing a single rotating permanent magnet as opposed to multiple rotatingmagnets, vibrations may be reduced.

FIG. 4 is a schematic perspective view of the motor assembly 1 withvarious other vibration-reducing components. For example, the flanges11A, 11B can be disposed about the flow diverter 3 and can mechanicallycouple with an interior surface of a motor housing 40.

In various embodiments, dampening elements are used to limit oreliminate transmission of vibration and noise from the rotating portionsof the motor assembly 1 to the rest of the motor assembly (e.g. housing40). In various embodiments, the rotation elements are connected to thestationary elements only through damping elements. A damping element41A, 41B can be disposed radially within the flanges 11A, 11B. An innerflange portion 44A, 44B can be disposed radially inward of the dampingelement 41A, 41B. Suitable materials and structures for the dampingelements include, but are not limited to, rubber, elastomers, polymers,springs, and the like. In the illustrated embodiments, the dampingelement 41A, 41B is formed of rubber, a thermoplastic elastomer (e.g.,polyurethane), or other damping materials understood by one of skill inthe art. In various embodiments, the damping elements comprise ananti-vibration mount formed of a relatively rigid element and acompression element. The inner flange portion 44A, 44B can be securedabout the outer surface of the flow diverter 3. In the illustratedembodiments, the inner flange portions 44A, 44B and the flanges 11A, 11Bcan be stiffer than the damping elements 41A, 41B. For example, in someembodiments, the inner flange portions 44A, 44B and the flanges 11A, 11Bcan comprise a plastic material and the damping element 41A, 41B cancomprise rubber.

Vibrations may be caused by the rotating components of the motorassembly 1, e.g., by rotation of the rotor 15, the output shaft 13, thedrive shaft 16, etc. The vibrations can be transmitted outwardly throughthe inner flange portions 44A, 44B to the damping elements 41A, 41B. Thedamping elements 41A, 41B can damp the amplitude of the vibrations suchthat minimal or no vibrations are transmitted through the flanges 11A,11B to the housing 40. Thus, the use of the flanges 11A, 11B, thedamping elements 41A, 41B, and the inner flange portions 44A, 44B canadvantageously reduce the transmission of vibrations to the housing 40and the patient. In various embodiments, the damping elements 41A, 41Bcan comprise one or more windows therethrough that provide for therouting of fluid and/or electrical lines through the motor assembly 1.Routing fluid and/or electrical lines through these windows can isolatethe fluid and/or electrical lines from strain that may be induced byrotating or moving components.

In addition, vibrations can also be caused by rotation of the driveshaft 16, for example, when the drive shaft 16 hits the catheter body120A. To reduce vibrations caused by rotation of the drive shaft 15, afitting 43 can be disposed in an opening of the motor housing 40 aboutthe catheter body 120A. The fitting 43 can comprise any suitable fittingthat damps vibrations (e.g., rubber). For example, the fitting 43 cancomprise a grommet disposed about the catheter body 120A. Vibrationsgenerated by the rotating drive shaft 16 can be transmitted outwardlythrough the catheter body 120A and can be damped by the fitting 43. Thefitting 43 can thereby attenuate and/or eliminate vibrations from beingtransmitted to the motor housing 40.

A strain relief feature 42 can also be provided on the exterior of themotor housing 40. The strain relief feature 42 can comprise a pluralityof holes through which wires can be routed to the motor assembly 1. Thestrain relief feature 42 can help to route the wires and can prevent thepatient or clinician from accidentally pulling on the wires that areconnected to the motor assembly 1.

In addition, the embodiments of the motor assembly 1 disclosed hereinare advantageously of smaller dimensions and smaller weight as comparedwith motor assemblies that use two rotating magnets, e.g., a drivemagnet and a follower magnet. In one example, a breadboard builtaccording to the description above was found to reduce the overalllength of the motor assembly 1 by about 20% and the overall weight byabout 40% by comparison to an equivalent assembly with rotor magnet andfollower magnet.

FIGS. 5A and 5B show one embodiment of an interface 22 between theoutput shaft 13 and the drive shaft 16. The interface 22 can comprise aconnection between a distal portion of the output shaft 13 and aproximal portion of the drive shaft 16. The distal portion of the outputshaft 13 can comprise a radially-inward taper and one or more holes 61formed through the output shaft 13. The proximal portion of the driveshaft 16 can be inserted within the lumen 55 of the output shaft 13 suchthat the lumen 55 and the inner lumen 58 of the catheter body 120A forma continuous passage. This passage can be used to advance the guidewireguide tube 20, sensors, and other instruments, or to provide fluidcommunication for cooling fluid or medications. Cooling fluid can flowproximally from the inner lumen 58 of the catheter body 120 and portionsof the fluid can pass outwardly about the periphery of the rotor 15.Other portions of the fluid can pass through the lumen 55 of the outputshaft 13. A sleeve 21 can be disposed about the proximal portion of thecatheter body 120A, and the seal 37 can be provided about the sleeve 21to seal the distal chamber 5 from the rotor chamber 4.

In the illustrated embodiments, the output shaft 13 can be permanentlycoupled with, e.g., laser welded to the drive shaft 16. For example, awelding machine can access the interface 22 by way of the holes 61formed in the output shaft 13 to weld the output shaft 13 to the driveshaft 16. In other embodiments, the output shaft 13 can be secured tothe drive shaft 16 in other ways, e.g., by friction or interference fit,by adhesives, by mechanical fasteners, etc.

Although the embodiments disclosed herein illustrate examples of heattransfer devices (such as the heat exchanger 30), it should beappreciated that other types of heat transfer devices may be suitable.For example, a thermal layer can be disposed within the housing andconfigured to transfer heat away from the stator and/or the rotor. Atleast a portion of the thermal layer can be disposed between the rotorand the stator assembly. In some embodiments, the thermal layer and heattransfer system may be employed without requiring external fins whichare exposed to the outside environs. In other embodiments, heat fins orother conductive elements can assist in transferring heat away from thestator and/or rotor and to the environment. For example, in someembodiments, internal heat fins or other conductive elements may bedisposed within the motor assembly 1 about the stator assembly 2, butmay not be exposed to the outside environs. In some embodiments, a fancan be disposed inside the motor housing to assist in dissipating heat.In some embodiments, the motor housing can comprise holes or vents tocause air to flow over the internal heat fins. In some embodiments, atleast a portion of the thermal layer is disposed within the rotor, e.g.,a lumen disposed within the rotor. In some embodiments, the thermallayer comprises a thermally conductive material. In some embodiments,the thermal layer comprises an inside layer of high thermal conductivity(for absorbing heat spikes) and an outer layer of low thermalconductivity (for dissipating heat into the environment slowly). Thethermal layer can also comprise a fluid pipe. In some embodiments, thethermal layer comprises a fluid chamber, the rotor configured to bedisposed in fluid in the fluid chamber. In some embodiments, the thermallayer comprises a heat exchanger with a plurality of coils, the coilsdisposed about a portion of the stator assembly 2 (or other parts of themotor assembly 1). In some embodiments, as explained above, the thermallayer can comprise a heat exchanger comprising a jacket or sleeve (e.g.,an annular cylinder) disposed about a portion of the stator assembly 2and/or other parts of the motor assembly 1.

Although the embodiments disclosed herein have been described withreference to particular embodiments, it is to be understood that theseembodiments are merely illustrative of the principles and applicationsof the present inventions. It is therefore to be understood thatnumerous modifications can be made to the illustrative embodiments andthat other arrangements can be devised without departing from the spiritand scope of the present inventions as defined by the appended claims.Thus, it is intended that the present application cover themodifications and variations of these embodiments and their equivalents.

1-41. (canceled)
 42. A catheter pump system comprising: an impeller; acatheter body having a supply lumen therethrough, and through which afirst fluid is supplied to a distal portion of the catheter body; adrive shaft disposed inside the catheter body and coupled with theimpeller at a distal portion of the drive shaft; and a motor assemblycomprising: a rotor mechanically coupled with a proximal portion of thedrive shaft; and a stator assembly disposed about the rotor andconfigured to cause the rotor to rotate; and a heat exchanger coupledwith the motor assembly to remove heat therefrom, the heat exchangercomprising a volume to receive a second fluid, wherein the heatexchanger is disposed about a portion of the stator assembly, andwherein the volume is in fluid isolation from the supply lumen of thecatheter body.
 43. The catheter pump system of claim 42, wherein thefirst fluid is a biocompatible coolant fluid.
 44. The catheter pumpsystem of claim 42, wherein the second fluid is a non-biocompatiblecoolant fluid.
 45. The catheter pump system of claim 44, wherein thesecond fluid comprises a refrigerant.
 46. The catheter pump system ofclaim 44, wherein the second fluid comprises a compressed gas.
 47. Thecatheter pump system of claim 42, wherein the heat exchanger furthercomprises tubing defining a lumen therethrough that further defines thevolume that receives the second fluid, the lumen extending from an inletto an outlet, the inlet in fluid communication with a supply reservoir,and the outlet in fluid communication with a waste reservoir.
 48. Thecatheter pump system of claim 47 further comprising a chiller coupled influid communication between the supply reservoir and the inlet of theheat exchanger, the chiller configured to cool the second fluid prior toits flowing into the inlet of the heat exchanger.
 49. The catheter pumpsystem of claim 42, wherein the motor assembly further comprises achamber in fluid communication with the supply lumen of the catheterbody and in fluid isolation from the heat exchanger volume, wherein therotor is disposed in the chamber.
 50. The catheter pump system of claim49, wherein the first fluid flows proximally from the supply lumen intothe chamber and about a periphery of the rotor.
 51. The catheter pumpsystem of claim 49, wherein the first fluid flows proximally from thesupply lumen into the chamber and through a lumen of an output shaft ofthe rotor.
 52. The catheter pump system of claim 49 further comprising awaste reservoir in fluid communication with an outlet of the chamber ofthe motor assembly, and wherein the first fluid flows proximally fromthe supply lumen into the chamber and through the outlet to the wastereservoir.
 53. A method of cooling a motor of a catheter pump system,the method comprising: directing a distal flow of a first fluid througha supply lumen of a catheter body of the catheter pump system, thecatheter body having a drive shaft disposed therein and coupled to animpeller at a distal portion of the drive shaft; directing a proximalflow of the first fluid through a chamber of a motor assembly of thecatheter pump system, the chamber having a rotor of the motor assemblydisposed therein; and directing a coolant flow through a lumen of a heatexchanger coupled about a portion of a stator assembly of the motorassembly, the lumen in fluid isolation from the supply lumen.
 54. Themethod of claim 53, wherein directing the proximal flow furthercomprises directing at least a portion of the proximal flow about aperiphery of the rotor in a gap defined between the rotor and a wall ofthe motor assembly.
 55. The method of claim 53, wherein directing theproximal flow further comprises directing at least a portion of theproximal flow through a lumen defined in an output shaft of the rotor.56. The method of claim 53, wherein directing the distal flow furthercomprises enabling a return flow proximally from the distal portion ofthe catheter body through an inner lumen of the catheter body.
 57. Themethod of claim 56, wherein enabling the return flow further comprisescoupling a waste reservoir in fluid communication with the inner lumenof the catheter body.
 58. The method of claim 53, wherein directing theproximal flow further comprises coupling a waste reservoir in fluidcommunication with the chamber.
 59. The method of claim 53, whereindirecting the coolant flow further comprises coupling anon-biocompatible supply reservoir in fluid communication with an inletof the lumen defined through the heat exchanger, and coupling a wastereservoir in fluid communication with an outlet of the lumen.
 60. Themethod of claim 59, wherein directing the coolant flow further comprisesdirecting a refrigerant through the lumen defined through the heatexchanger.
 61. The method of claim 59, wherein directing the coolantflow further comprises directing the coolant flow through a chillercoupled in fluid communication between the non-biocompatible supplyreservoir and the inlet of the lumen.